Techniques to support positioning for access points and terminals in WLANs and other wireless networks are described. In one aspect, WLAN positioning is supported with Secure User Plane Location (SUPL). A terminal obtains measurements for an access point in a WLAN and/or receives measurements made by the access point for the terminal. The terminal determines WLAN AP information for the access point and/or the terminal based on the measurements and sends the WLAN AP information to a SUPL Location Platform (SLP). The SLP determines a location estimate for the terminal based on the WLAN AP information. In another aspect, the terminal receives supported network information from the SLP. The terminal obtains network measurement information (e.g., measurements) for a radio access network and determines which particular network measurement information to send based on the supported network information. The terminal sends network measurement information permitted by the supported network information to the SLP.